New IPCC report: over 3bn people face rising climate-change threat

The Economist

New IPCC report: over 3bn people face rising climate-change threat

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THE ASSESSMENT REPORTS from the Intergovernmental Panel on Climate Change used to assess scientific extrapolations, the output of models and similar investigations into likely and frightening futures. The latest, sixth, assessment report, which comes eight years after the previous one, reflects how much has happened of late. It reads, for the first time, like something written from within the thick of things, an assessment of an ever more troubling present. The release of the first tranche of this new report, the bit that dealt with the state of the physical science of the climate system and climate change, came in August. The second tranche (of three, with a synthesis due later) arrived on February 28th. It reports on the impacts of that climate change, and on adaptation and vulnerability to it. Like the first, this second tranche is the work of hundreds of authors who have ploughed through vast piles of peer-reviewed papers and other material, with their work then scrutinised by both peers and governments. Researchers and government officials then gathered to agree on phrasing that summarises those findings and advice. The report as a whole is a huge, baggy and inevitably uneven affair. And as Nat Keohane, head of the Centre for Climate and Energy Solutions, an American think-tank, put it, At the most basic level, [it] simply confirms what we already know: the damages from climate change are occurring already. But what is known about the crisis that is under way bears some restating. The summary says clearly that things are getting worse, with observed increases in extreme high temperatures on land and in the seas, in torrential rain, in droughts and weather conducive to wildfires. The changes are affecting people, animals and plants, with widespread shifts in the timing of the seasons and with half of the species scientists have looked at moving towards higher latitudes and/or higher altitudes to cool down (though it is possible that there is some bias there: data may be gathered for species already thought to be on the move more than they are for others). With temperatures currently 1.1-1.3C above pre-industrial levels, some natural systems are approaching, or surpassing, their capacity to adapt. Some coral reefs, rainforests, coastal wetlands and polar and mountainous ecosystems are butting up against hard limits. Plants that humans use for food, fabric and other purposes are also under stress. The report notes with moderate confidence that the increases in agricultural productivity made over the past 50 years are lower than they would have been in the absence of climate change. Changes are not all slow and gradual. Where highly vulnerable populations face hazards such as extreme weather, climate change is contributing to humanitarian crises. People in all regions of the world are being displaced by them, it says. It highlights worsening food insecurity and malnutrition wrought by droughts and floods in Africa and Latin America. The report does not, however, see much of an impact from all this on violent conflict. Some things could have been worse. Some efforts towards development and climate adaptation, it says, have reduced vulnerability to climate change, and more planning for adaptation (and implementation of those plans) is being seen everywhere. Some of those programmes also bring benefits beyond their alleviation of climate risk. For all that, though, the impacts of climate change are increasing at a rate that outstrips those improvements in adaptation. In the near termperhaps the next few decadestrying to narrow that widening gap seems to be the most important task. The point is that the difference in near-term risk between worlds with better and worse adaptation is greater than between worlds with more or fewer emissions. Acting quickly, though, may come at the cost of neglecting plans for the long term. Actions designed to lower immediate risks, the report argues, can reduce the opportunity for transformational adaptation that improves things over the longer term. The report warns of risks from maladaptation in which efforts to address climate impacts do more harm than good. One example would be building a sea wall around a city. Doing so protects the residents from rising sea levels and storm surges in the short term. But it might also change the pattern of currents by the coast, creating worse erosion elsewhere. Such measures can also create a false sense of security: in the floodplain around the Jamuna river in Bangladesh, there is evidence that the presence of levees attracts more people to live there, ultimately increasing the number of deaths that result if a levee were to break. Starting an irrigation system in an area where the rain can no longer be relied upon to grow crops could lead to overconsumption of river water, leaving people downstream with less. In choosing the right solutions, we need to be thinking about more than just one climate hazard and also about the range of side-effects of the interventions we undertake says Maarten van Aalst, director of the Red Cross Red Crescent Climate Centre, and one of the reports authors. Even if such unintended consequences are avoided, there are signs that, in some areas, humans will struggle to adapt much more. Extreme heat is one example. Last summer, British Columbia in Canada recorded a freakishly high temperature of 49.6C. Almost simultaneously, Iraqis protested against electricity cuts as temperatures in the country exceeded 50C. The heatwave in Canada was more unusual than the one in Iraq. But Canada has the resources to prepare for another one, if it chooses. Iraq does not. These types of soft limits can be overcome, but not easily. In the case of Iraq, overcoming those soft limits would require simultaneously overhauling the attitudes and capacity of the government, reforming institutions and aligning donors to provide new sums of money. The fact that tangible damage is already here adds not just physical burdens but also political ones. Negotiation at the meetings of the UN Framework Convention on Climate Change, most recently in Glasgow last November, becomes particularly heated over what the convention calls loss and damage impacts which have already been felt, and over which developing countries have a case for compensation. Reportedly the biggest ructions in the closed plenary during which the IPCC summary was hashed out stemmed from attempts by some governments to make sure that it did not do too much to bolster the developing countries case. Politics are hardly a new addition to the IPCC process; it was created at the end of the 1980s in part to generate political buy in to scientists warnings. But from now on, with assessment a matter of the present, not the future, expect the tensions to grow.